1. Field of the Invention
The present invention relates to human-machine interface (HMI) of portable navigation devices.
2. Description of the Related Art
Driven by advancements in Global Positioning System (GPS) chips, modules, and components, lowering price and size thereof, GPS functions have increasingly been implemented in portable consumer electronic devices. The GPS can be applied in military, aviation, voyage fields, or even in mountain-climbing, positioning or car navigation systems. The car navigation device is the most popular one among the GPS devices.
Car navigation systems are typically divided into two categories: embedded navigation devices (for example, equipped in a car) or portable navigation devices. The portable navigation device may be a consumer electronic product specialized in GPS function or a consumer electronic product, such as a personal digital assistant (PDA) or a smart phone) having a navigation system built therein.
Conventionally, the portable navigation device is of simpler design than the embedded navigation device, but the GPS functions provided by the portable navigation device are enough for the basic use. Today, navigation devices, used mainly in cars, provide improved positioning functions, abundant graphics libraries (for dynamic navigation capabilities, weather condition forecasts, travel guides, voice sound navigation capabilities, online graphics library updates and so on) as well as being integrated with other popular applications.
Some portable navigation devices, used mainly in cars, are equipped with speech recognition functions. Users can operate the portable navigation device without physically touching the controls thereof. For example, users can use voice to operate the portable navigation device to provide information built therein or to provide information the device has retrieved from the network.
However, currently, speech recognition methods do not provide interactive communication between a user and a portable navigation system.